More than a decade later, the four hippos that Escobar bought from a private zoo in California have multiplied to 35 animals, an invasive species that spreads disease, predates on local fauna (including manatees) and livestock, and have been sighted as far as 150km away from Escobar's former home. The animals can live up to 60 years and there are no natural predators for them in Colombia. Further complicating the effort to control their reproduction is that it's incredibly hard to castrate a hippo: first, because it annoys the hippo; and second, because hippo testicles retract into their bodies, making it nearly impossible to sex a hippo without a rather intimate inspection.
The current strategy is containment-based: local vets and officials are trying to build a fenced-in habitat for the hippos that has everything they need to tempt them to stay, and a combination of natural and constructed barriers to keep them from wandering.
And you thought manatees were the apex predator!